It is desirable to provide parked aircraft with power, potable water, conditioned air and the like (collectively "utilities") from facilities within a passenger terminal or other ground-based facility. The prior art teaches that these can be supplied to a parked aircraft by attaching lines carrying utilities ("utility lines") to an extendable passenger loading bridge. See. e.q. U.S. Pat. Nos. 3,521,316 and 3,859,481. Through this arrangement, the utility lines will be extended and retracted by movement of the passenger loading bridge, without the need for an additional power source.
A difficulty with this approach is that the utility lines tend to become tangled, twisted or kinked upon repeated extension and retraction of the passenger loading bridge. The prior art refers to a number of approaches to this problem, none of which has been completely satisfactory. The '316 patent, for example, refers to a system of rollers and cables for suspending the utility lines from a passenger loading bridge. U.S. Pat. No. 4,620,339 (reissued as U.S. Pat. No. Re. 32,687) and U.S. Pat. No. 4,715,077 employ a related arrangement. U.S. Pat. No. 4,572,550 refers to a series of brackets attached to the passenger loading bridge by swivel mounts. These approaches are relatively costly and complex to use.
The '481 patent refers to suspending a series of trolleys from a single cable. U.S. Pat. No. 4,526,090 refers to a tray containing a Z-shaped connecting member that effects two 90.degree. turns in a partly flexible conduit. The devices of the '481 patent and the '090 patent are complicated and appear to be relatively expensive to manufacture. Moreover, those devices are not believed to prevent the utility lines from becoming twisted or kinked.